Comparing SQL Server and Redis performance

How to kill all database connections before dropping it?

USE master;
GO
DECLARE @sql nvarchar(max);
WHILE 1=1 BEGIN
    SELECT TOP 1 @sql = N'KILL ' + convert(nvarchar(10), spid)
    FROM sysprocesses WHERE dbid = DB_ID('my_database');
    IF @@rowcount = 0  BREAK;
    EXEC sp_executesql @sql;
END;
DROP DATABASE IF EXISTS my_database;

SQL Server Profiler has the template "locks" that is intended especially to trace deadlock. Let's try to simulate and catch a deadlock situation.

Suppose the test database is named test. Create two tables and feed them some data.

USE test;

CREATE TABLE dbo.invoices (
   id int NOT NULL,
   num nvarchar …

Update. Since the version 2016 SQL Server supports anonymous constraint declaration:

CREATE TABLE #temp_table (
   id1 int NOT NULL,
   id2 int NOT NULL,
   name1 nvarchar(100),
   name2 nvarchar(100),
   PRIMARY KEY (id1, id2),
   UNIQUE (name1, name2)
);

For earlier versions the solution is below.

Local temporary tables are isolated in the scope …

Hash indexes are used as entry points for memory-optimized tables; both features were introduced in SQL Server 2014. Let's look at index performance in scenario "key-value store".

Scenario and environment

The table stores a significant volume (about 10 millions rows) of pairs key-value. The key is of integer type and …

Unfortunately, SQL Server doesn't have a function like frac to extract the fractional part of number. The method is to subtract the integer part from the origin value.

DECLARE @n1 float, @n2 float, @n3 float;
SELECT @n1 = 123.456, @n2 = 234.567, @n3 = 456.789;
SELECT @n1 - round(@n1, 0 …

This small example shows how to synchronize the data of two tables using the MERGE statement

CREATE TABLE table1 (id int NOT NULL PRIMARY KEY, str_value nvarchar(50));
CREATE TABLE table2 (id int NOT NULL PRIMARY KEY, str_value nvarchar(50));
GO
INSERT INTO table1 (id, str_value) VALUES (1, 'Value 1 …

Here are some examples of SQL to generate a sequence of numeric (integer) values from 0 to 99.

ANSI-compatible

SELECT ones.n1 + tens.n2 * 10
FROM
(
  SELECT 0 AS n1
  UNION SELECT 1 AS n1
  UNION SELECT 2 AS n1
  UNION SELECT 3 AS n1
  UNION SELECT 4 AS n1 …

As DBAs know, Database Tuning Advisor can help you in some cases.

• The analyze of the traces will be efficient in OLTP where the most of queries are repeating and could be generalized
• The analyze of traces will be less efficient in OLAP/reporting where the queries are parameterized by …

How to insert fast a file (i.e. binary one) from disk to a SQL Server table?

Certainly the SQL Server account should have a corresponding permissions to access the file on the disk. For example I take the file C:\WINDOWS\system32\oembios.bin having the size about 12 …